Antoine Lavoisier — Chemist and Architect of the Chemical Revolution
Antoine Lavoisier transformed chemistry from a qualitative craft into a quantitative science, establishing the conservation of mass, overthrowing the phlogiston theory, naming oxygen and hydrogen, and building the modern system of chemical nomenclature. A tax collector in the ancien régime and a member of the revolutionary commissions on weights and measures, he also designed the first modern chemistry textbook and helped define the metric system. His execution during the Terror, and the question of whether France condemned a scientist or a tax farmer, made his death itself a landmark in the relationship between science and the state.
Events
Birth and Education in the Last Years of the Old Regime
Antoine-Laurent de Lavoisier was born in Paris on 26 August 1743 into the nobility of the robe, the son of an attorney at the Parlement of Paris, and inherited a large fortune at the age of five. From 1754 to 1761 he studied at the Collège des Quatre-Nations, where courses in chemistry, botany, astronomy, and mathematics under the astronomer Nicolas-Louis de Lacaille turned him toward experimental science. His earliest research, on the gypsum of the Paris basin and on the supposed conversion of water into earth, already showed his preference for precise measurement.
Location: Paris, France
Elected to the Academy of Sciences
In 1768, at twenty-five, Lavoisier received a provisional appointment to the Academy of Sciences, France's leading scientific body. The same year he bought a share in the Ferme générale, the private tax-farming company that advanced revenue to the crown in return for the right to collect taxes, one of the most hated institutions of the ancien régime. The income from the Ferme générale funded the laboratory and instruments that made his scientific work possible.
Location: Paris, France
Marriage to Marie-Anne Paulze
In 1771 Lavoisier married Marie-Anne Pierrette Paulze, the daughter of a senior member of the Ferme générale. She became his laboratory collaborator, learned English to translate the work of Joseph Priestley and others for him, kept the laboratory records, and produced the engravings that illustrated his Traité élémentaire de chimie. After his death she preserved and edited his papers and hosted a scientific salon in Paris.
Location: Paris, France
The Quantitative Study of Combustion
In memoirs presented to the Academy from 1772 onward, Lavoisier burned phosphorus, sulfur, and metals in sealed vessels and showed that the products weighed more than the original materials, the gain being taken from the air. By weighing everything before and after reaction he established that matter is neither created nor destroyed in chemical change, the law of conservation of mass. The experiments directly challenged the phlogiston theory, which had explained combustion as the release of a fire-like element.
Location: Paris, France
Commissioner of Gunpowder
In 1775 Lavoisier was made one of four commissioners of the newly reorganized Régie des poudres, replacing a private company that had supplied France's munitions badly. Under his administration the quantity and quality of French gunpowder improved greatly and the monopoly became a source of state revenue. The appointment gave him a house and laboratory in the Royal Arsenal, where he lived and worked from 1775 to 1792, and where he trained the young Éleuthère Irénée du Pont in powder-making.
Location: Paris, France
Oxygen and the Fall of Phlogiston
Lavoisier identified the gas that Priestley had produced from mercuric calcite as a chemical element, naming it oxygen in 1778, and explained combustion and calcination as combination with it rather than the release of phlogiston. In 1783, with Pierre-Simon Laplace, he demonstrated that water is a compound of hydrogen and oxygen, and that the "inflammable air" of the English chemists was itself an element. The work completed the chemical revolution begun with his quantitative experiments and gave chemistry a new theoretical vocabulary.
Location: Paris, France
A New Chemical Nomenclature
In 1787 Lavoisier, with Guyton de Morveau, Berthollet, and Fourcroy, published the Méthode de nomenclature chimique, replacing the old names derived from alchemy and from the supposed properties of substances with a systematic vocabulary built from the elements. Compounds were named for their constituents, so that "calx of mercury" became mercuric oxide and "fixed air" became carbonic acid. The reform was adopted rapidly across Europe and gave the science its modern names for acids, oxides, and salts.
Location: Paris, France
The Traité Élémentaire de Chimie
Published in 1789, the Traité élémentaire de chimie presented chemistry as a coherent science with a defined method, a balance sheet for every reaction, and the first extensive modern list of chemical elements, thirty-three substances that could not be broken down further. Lavoisier predicted the existence of silicon and included light and heat among the elements, a view later revised. The book became the standard text of chemistry across Europe and is often treated as the founding document of the modern science.
Location: Paris, France
The Metric System and the End of the Ferme Générale
In 1790 the revolutionary Assembly created a commission on weights and measures, on which Lavoisier served; in March 1791 it recommended the adoption of the metric system based on the meridian of the earth, and he worked out the practical tables and measures. The same revolution destroyed his livelihood: the Ferme générale was abolished in March 1791 amid popular hatred of the tax farmers. He continued administrative work for the new regime, including a report on the state treasury.
Location: Paris, France
The Arrest of the Former Tax Farmers
On 24 November 1793 the Revolutionary government ordered the arrest of all former Farmers General, charging them with defrauding the state and with selling adulterated tobacco. Lavoisier drafted the defense of the group, refuting the financial accusations and noting that the standard addition of water to tobacco had been an official regulation of the agency. The court was inclined to believe that condemning the tax farmers and seizing their goods would recover large sums for the state.
Location: Paris, France
Execution and Exoneration
Lavoisier was convicted and guillotined on 8 May 1794 in Paris, aged fifty, with twenty-seven co-defendants, despite appeals to spare him in recognition of his services to science. The mathematician Joseph-Louis Lagrange is reported to have said that it took an instant to cut off that head and a hundred years might not produce another like it. Eighteen months later the French government exonerated the former tax farmers, and Lavoisier's papers and instruments were returned to his widow.
Location: Paris, France